Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
danh hai » dang hai, lanh hai, manh hai
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, co sach
mai doi » moi doi, mai hoi, mai khoi
lai hoi » dai hoi, lai hoa, lai roi
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
hai cua » thai cua, dai cua, hoi cua
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang ((mai doi) or (lai hoi)). hieu ve cam thuc va danh hai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang ((mai doi) OR (lai hoi)). hieu ve cam thuc va danh hai cua viet.
• Adding a wildcard symbol may retrieve word variants: so sach y nang ((mai doi) or (lai hoi)). hieu ve cam thuc va danh hai cua viet*.